Accession Number : AD0764029

Title :   On the Number of Absolutely-Identifiable Spectral Hues.

Descriptive Note : Provisional rept.,

Corporate Author : JOHNS HOPKINS UNIV BALTIMORE MD PSYCHOLOGICAL LAB

Personal Author(s) : Halsey,Rita M. ; Chapanis,A.

Report Date : 10 JUL 1951

Pagination or Media Count : 11

Abstract : A normal observer can discriminate well over a million different colors under ideal, laboratory conditions of observation. How many colors can be identify when he sees colors singly and is required to identify them with nearly 100 per cent accuracy. The experiments reported here are an attempt to estimate the number of such absolutely-identifiable spectral hues. Observers were tested in a schedule which included familiarization, practice and test runs with four different series of spectral hues. In every case, the test colors were presented singly against a neutral gray background, and the observers were required to identify each according to a simple numerical code. Four series of spectral hues, containing 17, 15, 12 and 10 wavelengths, were used. The results suggest that the average observer can identify no more than 12 spectral hues under these conditions of observation. (Author)

Descriptors :   (*VISUAL ACUITY, *COLORS), IDENTIFICATION, ULTRAVIOLET SPECTRA, VISIBLE SPECTRA

Subject Categories : Psychology

Distribution Statement : APPROVED FOR PUBLIC RELEASE